液芯大压下轧机轧辊的热力耦合分析及疲劳寿命计算

Analysis and calculation of thermal-structural coupling and fatigue life of liquid core heavy reduction rolling mill's roller

液芯大压下轧机的技术难点是保证轧辊在恶劣工况下的正常工作寿命,它是连续生产的保障。本文采用有限元法中热力耦合的分析方法模拟堆焊型和辊套型两种轧辊的轧制过程,轧辊材料为综合力学性能较好的H13(4Cr5MoV1Si),计算其温度场、应力场和应变场。采用高温应变疲劳寿命法计算辊面产生疲劳裂纹寿命,应用断裂力学理论计算其裂纹扩展的寿命。经计算,辊套型轧辊热应力低于堆焊型轧辊,并且拥有更长的工作寿命。

The key technology of the liquid core heavy reduction rolling mill is the roller＇s normal life cycle in a poor work condition,which is the guarantee of continuous production.The built-up welding roller and roll-sleeve type roller are simulated and calculated in this paper,using material H13（4Cr5MoV1Si） which has better synthetical mechanical properties.Based on the metal cumulate damage theory and rupture mechanics theory,the forming and extending rules of the roll＇s fatigue cracks are studied,and the fatigue life is calculated.Comparing the built-up welding roll with roll-sleeve,it is shown that roll-sleeve has a lower stress level and a longer fatigue life than the built-up welding roller.